﻿Shader "UI/ImageGradient"
{
	Properties
	{
		[PerRendererData] _MainTex("Sprite Texture",2D) = "white" {}
	_StartColor("Start Color",Color) = (1,1,1,1)
		_EndColor("End Color",Color) = (1,1,1,1)
		[Toggle(VerticalDirection)] _VerticalDirection("Vertical Direction",Int) = 0

		[HideInInspector] _StencilComp("Stencil Comparison",Float) = 8
		[HideInInspector] _Stencil("Stencil ID",Float) = 0
		[HideInInspector] _StencilOp("Stencil Operation",Float) = 0
		[HideInInspector] _StencilWriteMask("Stencil Write Mask",Float) = 255
		[HideInInspector] _StencilReadMask("Stencil Read Mask",Float) = 255

		[HideInInspector] _ColorMask("Color Mask",Float) = 15

		[Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip("Use Alph Clip",Float) = 0
	}

		SubShader
	{
		Tags
	{
		"Queue" = "Transparent"
		"IgnoreProjector" = "True"
		"RenderType" = "Transparent"
		"PreviewType" = "Plane"
		"CanUseSpriteAtlas" = "True"
	}

		Stencil
	{
		Ref[_Stencil]
		Comp[_StencilComp]
		Pass[_StencilOp]
		ReadMask[_StencilReadMask]
		WriteMask[_StencilWriteMask]
	}

		Cull Off
		Lighting Off
		ZWrite Off
		ZTest[unity_GUIZTestMode]
		Blend SrcAlpha OneMinusSrcAlpha
		ColorMask[_ColorMask]

		Pass
	{
		Name "UIImage_Gradient"
		CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0

#include "UnityCG.cginc"
#include "UnityUI.cginc"  

#pragma multi_compile __ UNITY_UI_ALPHACLIP

		struct appdata_t
	{
		float4 vertex : POSITION;
		float4 color : COLOR;
		float2 texcoord : TEXCOORD0;
		UNITY_VERTEX_INPUT_INSTANCE_ID
	};

	struct v2f
	{
		float4 vertex : SV_POSITION;
		float4 color : COLOR;
		float2 texcoord : TEXCOORD0;
		float4 worldPosition : TEXCOORD1;
		UNITY_VERTEX_OUTPUT_STEREO
	};

	uniform sampler2D _MainTex;
	uniform fixed4 _TextureSampleAdd;
	uniform float4 _ClipRect;
	uniform fixed4 _StartColor;
	uniform fixed4 _EndColor;
	uniform int _VerticalDirection;

	v2f vert(appdata_t IN)
	{
		v2f OUT;
		UNITY_SETUP_INSTANCE_ID(IN)
			UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(OUT)
			OUT.worldPosition = IN.vertex;
		OUT.vertex = UnityObjectToClipPos(OUT.worldPosition);

		OUT.texcoord = IN.texcoord;

		OUT.color = IN.color;
		return OUT;
	}

	fixed4 frag(v2f IN) : SV_Target
	{
		float4 tex = tex2D(_MainTex,IN.texcoord);

		float validFactor = IN.texcoord.x;
		if (_VerticalDirection != 0)
		{
			validFactor = IN.texcoord.y;
		}

		float4 validBlendColor = lerp(_StartColor,_EndColor,validFactor)*IN.color;
		fixed4 color = tex*validBlendColor;
		color.a *= UnityGet2DClipping(IN.worldPosition.xy,_ClipRect);

#ifdef UNITY_UI_ALPHACLIP
		clip(color.a - 0.001);
#endif

		return color;
	}
		ENDCG
	}
	}

}